Raising the nutrition bar

Energy bars are never a replacement for a good meal, but they can be a reasonable snack - sometimes.

Let's go through the most popular varieties.

High-protein: Excess protein is not going to help you build muscle, unless, of course, you are a body builder, in which case you would need more calories from all food groups. Americans eat too much protein (given our big portions and our current weight crisis), and too much protein taxes the kidneys.

Protein gets filtered in the kidneys, carbohydrates and fat in the liver. And the kidneys can only take so much. Look for bars with no more than 10 grams protein. For a 150-pound person, about 65 to 70 grams protein is recommended (depending on other health variables) per day. Some protein bars contain 35 to 45 grams of protein - that's over half your daily recommendation and you haven't eaten yet.

High-carbohydrate: Unless you're an endurance athlete, high carbohydrate nutritional bars are not necessary. Some have as much as 45 grams carbohydrates of which 20 come from sugar. If you're looking for weight loss, these bars are counterproductive. Look for bars with no more than 15 grams sugar.

Low-carbohydrate: If a bar is low in carbohydrates, then it's likely high in protein. Protein is not the body's preferred source of energy for exercise: carbohydrates are. Also, low-carb bars often use sugar alcohols as a substitute for sugar. Sugar alcohols may keep calories low, but they have unpleasant side effects, such as gas, bloating and diarrhea. Avoid bars loaded with ingredients ending in "ol" (sorbitol and xylitol).

Supplement bars: Supplement bars are a catch-all category that include other types of energy bars, and there are a lot. No nutritional/energy bar is going to increase brain function. It may contain or claim to contain special herbs or amino acids to "enhance the mind," but there's no evidence anywhere to back this claim up.

Remember: if sounds too good to be true, it probably is. The run of the mill energy bars also contain a lot of calories. Clif's Cookies 'n Cream bar has 250 calories - that's more than a Nestle Crunch bar. Admittedly, it does contain fiber, but I'm not sure it's worth the trade-off. Have an apple with some peanut butter, and you'll get energy, nutrients and fiber - all without chemicals and additives.

Low-glycemic bars heath claims would be difficult to prove because glycemic index is only measurable one food at a time, not with a combination of ingredients. For example, a plain almond with no salt. Adding salt changes the glycemic index.

Soy bars are the newest rage. They may help lower cholesterol, but the jury is still out on lowering risks for breast and prostate cancer. Some studies have even proven the opposite. They are, however, relatively low in calories (130 to 140) and high in fiber (3 grams).

Tribune Media Services is a division of Tribune Co. Betsy Klein is a registered dietitian based in Miami.

INFORMATIONAL BOX:

Energy bars

Properly chosen, energy bars can be a good snack. Here's what to look for:

Choose a bar with somewhere between 3 to 5 grams fiber. It should have no more than 150 to 225 calories. If it's a small bar and on the higher end of this scale, it's too caloric dense.

Don't judge a bar by its vitamin or mineral supplements. You're better off with a basic multivitamin or real food.

Look for no trans fat or anything hydrogenated and little saturated fat. Most bars contain 2 to 4 grams saturated fat, but some have as much as 8 grams. Read labels.

Avoid the biggie bars. They can creep up to 300 to 400 calories, about what would be in a peanut butter and jelly sandwich on whole wheat bread and way too much saturated fat.

Choose whole foods over a bar. But if your choice is no breakfast or a bar that fits within the parameters above, then a bar can be part of your breakfast or snack rotation.